Switch-mode power converters are commonly used in electronic applications to shift direct current (DC) power levels. For example, switch-mode power converters are used in switching power supplies, in AC inverters and pulse width modulated motor controllers. Switching frequency in the range a tens of kilohertz is typically used so the size and weight of magnetic components, such as transformers and inductors, are much smaller than components typically used in linear devices.
However, switch-mode power converters have disadvantages which can make them unsuitable for certain applications. For example, switch-mode power converters can be a source of different types of interference. In particular, electronic noise can be conducted on the output terminals. In addition, the switching action of switch-mode power converters radiates acoustic noise which can interfere with other equipment. Other noise produced by switch-mode power converters includes electromagnetic interference produced by the switching transients. Typical switch-mode power converters attempt to mitigate the effects of generated noise through filters, RF shielding, and/or noise cancellation electronics with digital signal processing algorithms. In the case of submerged applications, where components are maintained at ambient pressure inside an oil pressure balanced enclosure, it is essential to simplify and minimize electronic circuit components to obtain suitable reliability in that type of environment.
For the reasons stated above and for reasons that shall become apparent to one of ordinary skill in the art upon reading and studying the present application, there is a need in the art for a system which effectively cancels radiated noise from a switch-mode power converters.